Heinkel He 116 Rocket Assisted Take Off trials in the late 1930s

The Heinkel He 116 was an extremely long-range mail plane designed to deliver airmail between Germany and Japan. Several examples were built for this role, as well as a small batch to be used in the long-range reconnaissance role.

This was the third prototype of the type modified for record breaking long-range flight, to this end it was carrying so much fuel that RATO rockets were needed to get it into the air.

V3 was removed from the line to be converted into a record-breaking prototype. The modifications included a larger 75.6 m2 wing with a 25 m span, and increased fuel tankage in the fuselage. The 180 kW (240 hp) Hirth HM 508H engines provided a better fuel economy through operation at lower rpm. For take-offs with maximum fuel the He 116R, Rostock, was fitted with four RATO units. On its first record flight attempt (visible at 3:46) one of the rockets tore loose and hit the wing, requiring extensive repairs. After repairs were completed a second attempt was made on 30 June 1938, successfully covering 9,942 km unrefueled, at an average speed of 214 km/h.